I'm installing split flaps on a foam wing. I'd rather have them flush with the wing, not just laying on top. What is the best method to rout out the depth of the flap in the foam? I'm thinking of using a dremel, but I'm unsure of a bit to use, or how smooth the surface will be after routing. Any help or ideas?

I have taken flat sheet aluminum, taped it to the wing, folded the short side over a piece of piano wire (before tapeing to the wing), and ran that back into the fuselage through an aluminum tube, i.e., torque rod. More difficult to explain than do.

Is the foam sheeted with balsa? If so, just take a soldering iron and carefully melt foam away. Then line the cavity with balsa and build up the flaps, etc.

The wings are all foam. I saw a video where a guy used a dremel with a tile cutting bit to rout out that portion of the trailing edge to just the depth of the flap he was using. (a paint stirer stick I believe). When done the flap closed level/flush with the surface of the wing on the bottom. He made a nice job of it, and the routed portion was nice and smooth, so when the flaps were down, and that upper portion was painted, it looked really nice. Unless I can think of or get a better idea, I think that is the way I will go.
Thanks.

The wings are all foam. I saw a video where a guy used a dremel with a tile cutting bit to rout out that portion of the trailing edge to just the depth of the flap he was using. (a paint stirer stick I believe). When done the flap closed level/flush with the surface of the wing on the bottom. He made a nice job of it, and the routed portion was nice and smooth, so when the flaps were down, and that upper portion was painted, it looked really nice. Unless I can think of or get a better idea, I think that is the way I will go.
Thanks.

Went and got the tile cutter bit--lucky they had it. Just routed out the spots for the flaps---smooth and nice. Paint sticks cut to size and fit like a glove. Now to get some hinges. I have a few HK (4) hatch type hinges that I think will work well, and look the part. Now to rout the spots for the servos.
Need an opinion----I could use a servo reverser on one, or I could just mount them in the same direction. Aesthetically I should use the reverser, but once I tape them over and paint the tape and other horns and clevises they will be all but invisible. Thoughts?

If you can solder, you can just reverse one of the servos. Better to Youtube the instruction. I did it on a Stuka I put together, and it works very well. No reverser required, and they end up like bookends ------Metalguy

If you can solder, you can just reverse one of the servos. Better to Youtube the instruction. I did it on a Stuka I put together, and it works very well. No reverser required, and they end up like bookends ------Metalguy

A while back I tried doing that to a couple of old cheapo servos I got from Ebay. Did OK until I had to see the tiny little spots where the wires had to be soldered. My 63 year old eyes just aren't good enough. Bodged them both, so I have given that part of my model building up. I can solder pretty good, but tiny bits are out. Thanks for the suggestion.

A while back I tried doing that to a couple of old cheapo servos I got from Ebay. Did OK until I had to see the tiny little spots where the wires had to be soldered. My 63 year old eyes just aren't good enough. Bodged them both, so I have given that part of my model building up. I can solder pretty good, but tiny bits are out. Thanks for the suggestion.